I heard somewhere that the fungicide Rose Pride was less toxic to beneficial insects than plain baking soda. Is this true? I’d like to continue to use it in my garden.
Rose Pride is the chemical Triforine. I was not able to find any articles which suggest it is safer for beneficial insects than baking soda. Pesticides Action Network’s Pesticides Database indicates it is toxic in varying degrees to some forms of aquatic life. It is on the PAN List of “Bad Actor” pesticides, which means it belongs to a group of pesticides classified as most toxic (because they are known or probable carcinogens, reproductive or developmental toxicants, etc.). The Extension Toxicology Network also has a profile for this pesticide. Here are excerpts:
“In the United States, triforine is marketed for use on almonds, apples, asparagus, blueberries, cherries, hops, ornamentals, peaches and roses. Triforine is a ‘restricted use’ pesticide (RUP) with an EPA toxicity classification of I (highly toxic). Check with specific state regulations for local restrictions which may apply. Products containing triforine must bear the Signal Word ‘Danger’ on their label.
Triforine and the formulated product Saprol are considered of low hazard to honeybees and to the predatory mite Typhlodromus pyrii. It is also of low hazard to earthworms at recommended dose rates.”
My comment would be that “low hazard” is not the same as no hazard, and since there are many other areas of concern with this highly toxic product, it would be best to find an alternative. Locally, the Woodland Park Rose Garden converted a pesticide-dependent landscape to an organic one, and the roses look better than ever. (See an article about the garden from the Seattle Times.) Many gardeners are learning to live with a bit of black spot on their roses, and manage the disease by maintaining good garden hygiene. Don’t leave fallen leaves on the ground. Give your roses good air circulation, and keep the leaves dry when you water your plants. Mulching with wood chips can help, too, since they may prevent water from splashing up onto the leaves.
When deciding whether to treat a garden problem with pesticides, the “Precautionary Principle” provides an important perspective:
“When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.”